Wheel device



4 Sheets-Sheet 1 July 12, 1938. A. BLOCH WHEEL DEVI GE Filed June 26, 1957 INVENTOR. ArthurBbqch II I III III Fig. 3

II III July 12, 1938. oc 2,123,707

WHEEL DEVICE v File drJune 26, 1937 45heets-Sheet 2 INVENTOR.

Arthur Bloch a ATTORNEY.

ill i Ju1 12,193s. A. BLOCH 2,123,707

WHEEL DEVICE Filed June 26, 1957 q 4 Sheets-Sheet 3 l 3 l L INVENTOR.

ATTORNEY.

A. BLOCH WHEEL DEVICE July 12, 1938.

Filed June 26, 1937 4 Sheets-Sheet 4 Patented-July 12, 1938 31 UNITED STATES PATENT OFFICE WHEEL nEvIoE Arthur Bloch, New York, N.Y.

. Application June 26, 1937, Serial No. 150,472 Claims. (01. 16-44) This invention relates to wheel devices and par- Figure 13 is a side View of the device of Figure ticularly to caster wheel. devices for tables and 12.in'un1oaded condition.

the like. Figure 14 is a side view of the device of Figure For improving the function of suchdevices on .13 in loaded condition immediately in front of a 5 uneven ground it has been already proposed to threshold. 5 mount the wheel on its support by means of a ,Figure 15 is a side view showing the device of link influenced by a spring. It'has been found, Figures 12 to 14 on the threshold. however, that thereby theaction is improved only It is to be understood that in all the construcwith respect to depressions in the ground whereas tions the parts, links, bolts etc. on one side of the passing over elevated obstacles like thresholds Wheel are substantially duplicates of the parts 10 Figure 9 is "a rear view of Figure'ti looking in in Figure 13.

etc., remains diflicult' and tiresome particularly on the other side of the wheel. In other words if the'table or the like is moved by pushing inthe parts are arranged in pairs.' Therefore it stead-of pulling. F. will be sufiicient to describe the partson one side The inventor has found that this is caused of the wheel only. In some cases the parts may 3 mainly by thefactthat the :former devices are be arranged on only one side of the wheel. constructed in such manner tha't'the impact of Referring now to the construction in Figures 1 thewheel against an elevated obstacle causes a to 3 the caster wheel I is mounted on the support tendency for a sudden rise of the forward end oryoke 2 which is rotatable around the pivot 3 of the table and some kind of downward reaction in the usual manner. The wheel I is mounted on on' the wheel. the support 2 by means of the link 3 which is 20 In' distinction therefrom inthe' object of the pivoted on the bolt 4 of the sup-port and on its invention the wheel is yieldingly mounted on a lower ,end carries the axle 5 of the wheel I. A supportin such amannerthat by the impact of spring 6 is mounted on a bolt 1 of the yoke, and the wheel against an elevated obstacle is caused by its .free end presses forward the axle 5 and 2.3 a tendency-otthesupport to descend. I the lower end of the link 3 until the forward edge The invention will now be described with refof the link engages a. stop 8 projecting from the erenc to the accompanying drawings in which sup-port 2. In this condition the link 3 has passed Figurel is a side elevation of one form of conslightly beyond its vertical position and is in a struction' of the" object of the invention in the steeply upright position. Therefore any vertical 3o moment of reachinga threshold; load applied to the support 2 has simply the ef- .50

Figure 2 is a rear view 'looking'in the direction fect of pressing the link 3 in firmer engagement of the arrow A in Figure 1. V with the stop 8, and for this reason the load is Figure 3 shows thenevice of Figure 1 on the supported rigidly in h m manner as y any threshold. ordinary rigid wheel mounting. Figure 4 is a side view era modification in un- If, however, the wheel, travelling on the even :3 loaded condition; 3 floor 9 in the direction of the arrow B encounters "Figure 5 is a rear view of Figure 6 lookingin an elevated obstacle like the threshold I B, the the direction-of the arrow A in Figure 4; Wheel is arrested. The axle 5 now acts as a sta- Figure 6 shows the device of'Figure 41h loaded tionary pivot around which the link 3 with the conditionimmediately in front of the threshold. support 2 swings forwardly d wnwardly o to Figure 7 isa side elevation showing thedevice that the link 3 approaches a e horizontal D f re and 6 on the threshold; sition. Thereby it is made very easy for the Figure 8 is a side view of a further modifica- Wheel to climb the 'f tion in unloaded condition. A nose ll of the link 3 is adapted to contact the direction of the arrow ,A. merit of the link Figure 10 is a side view showing the device of g i gg i s- 3; 5255 213 5; 2.21 1 212222 3 5 Figure 8 in loaded condition immediately in front The desired action is assisted Very much by of thresholfiauxiliary roller l3 mounted on a pivot M on the F1 IS a slde 'elevatlon showmg'the lower front corner of the support 2 considerably vice of F u e 8 0n th thr ld- .ahead of the bolt or pivot 4. When by the im- Figure 12 is a front View'of a St l ur h dc pact of the wheel I against the threshold ID the fication looking in the direction of thearrOWA support 2 descends the auxiliary wheel or roller w 13 comes inengagement with the upper surface the stop 8 for preventing a too extended move- 45' of the threshold II) at a point ahead of the front of said threshold for a distance much longer than the link 3, relieves the wheel I from at least part of the load, and because of said long distance makes it easier for the wheel to climb the threshold, as clearly shown in Figure 3.

With the modifications now to be described the climbing of thresholds etc. is facilitated by a double mobility.

In the modificationshown in Figures 4 to '7 the axle 5 of the wheel I is supported by a link I! the other end of which is connected by a bolt I8 with a second link I9 pivoted on the bolt 4 on the rear lower corner of the support 2*. A spring 23 is coiled around the brake bolt I and presses with its free hook shaped end against the axle 5; Another spring 2I is coiled around the end of the pivot 4 and presses with its free end against the pivot I8, whereby the front edge of the link I9 is pressed against a stop 24 supported by the yoke 2 Figure 4 shows the parts in unloaded condition of the device. In this conditionthe link I9 points downwardly fromthe bolt 4, and the link I'I points forward and slightly upward from the pivot I8,

When a load is applied to the support 2 said support is lowered whereby the link I1 is swung upward around the pivot I8 until the link I 'I is substantially vertical and overlaps the link I9, as illustrated in Figure 6. During thismovement the spring 2Il'yields.

Because of the substantially vertical position of the links II and I9, the load is supported rigidly by the wheel.

When the wheel I rolling on the even floor 9 in the sense of the arrow B meets the threshold IO the link II remains substantially upright, whereas the link I9 swings around the pivot I8 forward and downward to substantially the position shown in Figure 7, whereby the support 2 is lowered and it is made easier for the wheel I to climb the threshold ID as shown in Figure '7. A nose 23 on link I9 prevents a too extended movement of the link by engagement with the stop 24 on the support 2*.

In this as well as in the other modifications the action is improved by auxiliary wheels or rollers I3, the lowermost points of which are located ordinarily at a higher level than the lowermost point of the wheel I so that these auxiliary rollers usually do not support any load, but can relieve the wheel I in climbing a threshold because of the distance between the pivots 4 and I4.

The moment the wheel I passes the threshold, the wheel snaps down again to the position shown in Figure 6 under the influence of the springs.

Now the modification shown in Figures 8 to 11 is to be described.

The wheel I is supported in the support or yoke 2 by means of the links and '3I. The link 30 is mounted on the bolt I4 supporting the auxiliary roller I3 on the support 2 The link 3| is connected with the link 30 by means of a bolt or pivot 32 and is connected at its other end with the axle 5 of the wheel I. A spring 33 is supported by the bolt I and presses by its hook shaped end 34 against the axle 5, whereby, in unloaded condition, the parts are held in the positions shown in Figure 8. In accordance with Figure 8 the link 30 is pointing downward and rearward, whereas the link 3| is pointing forward and upward substantially overlapping the link 30. In this condition the hook shaped end 35 of another spring 33 is idly supported by a bolt 36 provided on the support 2.

The support 2 is provided with an arc-shaped guide surface 36 against which the upper front surface 38 of the link 3I abuts.

When load is applied to the support 2 the spring 33 yields, and the parts move more or less to the positions shown in Figure 10, in which the spring hook 35 has entered into engagement with the axle 5. During this movement the surface 38 is guided by the guide surface 36 which takes up the load so that normally this device acts like a normal rigid caster wheel device.

When, however, the wheel I meets a threshold I 0 the link 30 swings downward around the pivot 32 whereby the support 2 is lowered. The spring 33 yields permitting this movement. By the latter the rear edge 31 of the support 2 passes beyond the front 39 of the link 3I and, thereupon, travels downward along the front edge 40 of the link 3| until the guide surface 36 engages a stop 4I provided on said front edge for preventing further movement of the parts.

By these movements and displacements of the parts it is made easy to the Wheel I to climb the threshold II) as shown in Figures 10 and 11.

As soon as the wheel I passes the threshold I I] it snaps again to the position shown in Figure 10 under the influence of the springs.

Of course also this modification can be provided with a brake substantially as described in connection with the former modifications, such brake being supported also by the rotatable support 2 In the modification shown in Figures 12 to 15 a double mobility of the wheel I on the'support 2 is obtained by means of a single link.

The axle 5 of the wheel I is supported by a link 42 provided with a'slot 43 in which is slidably received a bolt 44 supported by the support 2. To the latter is secured an arc-shaped rigid part 45 provided with a guide surface 46 for that end of the link 42 which supports the axle .5. The bolt 1 supports a spring 41, the hook shaped end 48 of which presses against the axle 5 thereby holding the parts in unloaded condition in the position shown in Figure 13. In this position a. pin 49 of the support 2 engages into a slot 50 provided in the front edge 5| of the link 42, thereby securing the parts in their positions.

In the position shown in Figure 13 the shank 52 of a second spring 4'I is idly supported by a pin 53 projecting inwardly from the guide part 45.

When load is applied to the support 2 the link 42 swings around the pivot 44, to the position shown in Figure 14. During this movement the front surface 54 of the link 42 travels along the guide surface 46 which acts as an abutment taking up the load until substantially the position shown in Figure 14 is reached. Because of this abutment action of the part 45 the device acts like any ordinary rigid caster wheel device on even ground.

When, however, the wheel I meets a threshold II) the link 42 swings forward around the axle 5 and the rear surface 55 of the abutment 45 slides downward along the front surface 5I 01' the link 42, whereas the bolt 44 travels downward in the slot 43 until substantially the position of Figure 15 is reached in which the bolt 44 abuts against the'end surface of the slot 43. During this movement the shank 52 of the spring 41 is engaged and further tensioned by the axle 5 as shown in Figure 15.

Therefrom it can be seen that the link 42 has a swinging relative movement around the axle and a sliding relative movement along the bolt 44 and that the link 42 in its action is similar to a scale beam supported on the bearing surface 55.

Also in this modification by the impact of the wheel I against the threshold Ill an initial tendency to descend is caused for the support 2 until the auxiliary rollers I 3 engage the upper surface of the threshold.

The moment the wheel I passes the rear edge of the threshold the wheel is snapped back to the position shown in Figure 14 by the spring.

It has been found that all the modifications function satisfactorily without use of the auxiliary wheels. By the latter, however, the action is very much improved.

What I claim is:

1. A wheel device and particularly a caster wheel device comprising in combination a. wheel normally supporting the load in a positive manner, a support for said wheel, a link mechanism for connecting said wheel with said support, spring means adapted to snap said wheel downwardly behind projections of the floor, said link mechanism normally transmitting the load reaction of said wheel positively to said support, a link of said link mechanism normally constituting a. rigid thrust member abutting against said support from below, abutment means on said support adapted to prevent forward and upward movement of said link and wheel under normal conditions but to permit upward and backward movement of said link and wheel after said link will have been knocked clear of said abutment means by the impact of said wheel against an obstacle.

2. A device as in claim 1 in which stop means are provided for preventing a too extended upward movement of said link.

3. A device as in claim 1 in which said link is connected with said support by a pivot and with said wheel by the axle of the latter and is held by the load reaction against said abutment means so that normally said axle is located below and slightly ahead of said pivot.

4. A device as in claim 1 in which said link is pivotally connected with a second link which, in turn, is pivoted to the axle of said wheel, said spring means including first spring means tending to hold said link against said abutment means, in unloaded condition of said wheel, in a downwardly pointing position, and additional spring means, tending to hold said second link in a, forwardly pointing position in said unloaded condition, whereas by the weight of the load said second link is swung upward, against the force of said additional spring means, to a position substantially parallel with said first link, and by the impact of said wheel against an obstacle said first link is swung to a less upright position against the force of said first spring means, but said second link is lifted in and to an upright position against the force of said additional spring means.

5. A device as in claim 1 in which said link is pivoted to the wheel axle and to a second link in turn pivoted to said support, and in which on said support a, guide surface is provided as the load supporting abutment for said link, said spring means tending to hold said link under said abutment.

ARTHUR BLOCI-I. 

